scholarly journals The Effects of Doping Copper and Mesoporous Structure on Photocatalytic Properties of TiO2

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yang Wang ◽  
Wubiao Duan ◽  
Bo Liu ◽  
Xidong Chen ◽  
Feihua Yang ◽  
...  

This paper describes a system for the synthesis of Cu-doped mesoporous TiO2nanoparticles by a hydrothermal method at relatively low temperatures. The technique used is to dope the as-prepared mesoporous TiO2system with copper. In this method, the copper species with the form of Cu1+, which was attributed to the reduction effect of dehydroxylation and evidenced by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), was well dispersed in the optimal concentration 1 wt.% Cu-doped mesoporous TiO2. In this as-prepared mesoporous TiO2system, original particles with a size of approximately 20 nm are aggregated together to shapes of approximately 1100 nm, which resulted in the porous aggregate structure. More importantly, the enhancement of the photocatalytic activity was discussed as effects due to the formation of stable Cu(I) and the mesoporous structure in the Cu-doped mesoporous TiO2. Among them, Cu-doped mesoporous TiO2shows the highest degradation rate of methyl orange (MO). In addition, the effects of initial solution pH on degradation of MO had also been investigated. As a result, the optimum values of initial solution pH were found to be 3.

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3349 ◽  
Author(s):  
Pablo A. Ochoa Rodríguez ◽  
Tamara B. Benzaquén ◽  
Gina A. Pecchi ◽  
Sandra G. Casuscelli ◽  
Verónica R. Elías ◽  
...  

Titanium dioxide materials were synthesized using two different methods. The samples were characterized by X-ray diffraction (XRD), UV–Visible diffusion reflectance spectroscopy (UV-Vis DR), Raman spectroscopy, N2 adsorption/desorption, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron spectroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Although both kind of materials were found to have mesoporous structure and anatase crystalline phase, one of them was obtained from a synthesis method that does not involve the use of surfactants, and therefore, does not require calcination at high temperatures. This implies that the synthesized solid was self-doped with carbon species, coming only from the same source used for titanium. Then, the relationship between the presence of these species, the final calcination temperature, and the photocatalytic activity of the solids was studied in terms of the degradation and mineralization of an Acid Orange 7 aqueous solution, under visible radiation. A photosensitizing effect caused by the non-metal presence, that allows the solid to extend its absorption range, was found. Hence, a novel route to prepare C-modified photoactive mesoporous TiO2, simpler and cheaper, where neither a template nor an external carbon source is used, could be performed.


2012 ◽  
Vol 550-553 ◽  
pp. 383-387 ◽  
Author(s):  
Fu Zhen Zhao ◽  
Wen Qiang Liang ◽  
Sheng Bin Ling ◽  
Yu Qing Wu ◽  
Ai Qing Zhang

A series of CuxCe1-xO2-x/SBA-15/cordierite (x = 0-1) catalysts were prepared. The activity of the catalysts for CO combustion was evaluated. The catalysts were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, and X-ray photoelectron spectroscopy (XPS). Deactivation behavior of the catalysts for the catalytic combustion of CO was investigated. The results show that all of the catalysts retained the SBA-15 mesoporous structure. It is proposed that deactivation of the catalysts is associated with the increase of the Cu+ and the decrease of the Cu2+ in the catalysts.


2020 ◽  
Vol 10 (5) ◽  
pp. 726-731
Author(s):  
Bin Zeng ◽  
Wujun Zeng

Introduction: Solid porous carbon (SPC) with micro-mesopore structures was successfully fabricated from used cigarette filters via carbonization. Experimental: The morphology and structure of the as-prepared porous carbon materials were characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Results: This novel carbon material allows the removal of organic pollutants from water. The maximum adsorbed capacity of methylene blue could reach ~185 mg.g-1, which was attributed to the high specific surface area (567.7 m2.g-1) and the micro-mesoporous structure of the samples. Conclusion: Furthermore, when genomic stability was maintained in the solution, SPC was easily extracted. The mechanism for the fabrication of the proposed used cigarette filter is elucidated in this study.


2010 ◽  
Vol 663-665 ◽  
pp. 243-246
Author(s):  
Han Mei Hu ◽  
Chong Hai Deng ◽  
Qiang Fang ◽  
Ya Gao ◽  
Meng Wei Song

In this paper, we report a simple two-step approach (microwave-calcinating) to prepare skin-colored N-doped ZnO nanocrystals. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS) and UV-visible absorption were used to characterize the as-synthesized products. The FESEM results reveal the products mainly take on the morphology of porous flake constructed by 20 nm nanoparticles. UV-Vis spectrum shows a strong absorption peak located at 384nm.


2010 ◽  
Vol 4 (3) ◽  
pp. 99-106 ◽  
Author(s):  
Izabela Szafraniak-Wiza ◽  
Bozena Hilczer ◽  
Ewa Talik ◽  
Adam Pietraszko ◽  
Barbara Malic

Simple perovskite nanopowders were fabricated by mechanochemical synthesis. High-energy milling process of respective oxides, leading to production of ferroelectric perovskites, was carefully investigated and characterized by X-ray diffraction, electron microscopy and X-ray excited photoelectron spectroscopy. It has been found that: (i) the powder consists of loosely packed grains with a broad distribution of sizes between a few nm and 45 nm, (ii) the grains possess core/shell structure, (iii) the grain core of sizes larger than about 20 nm exhibits well developed crystalline structure, (iv) the grains are coated by structurally disordered (amorphous) shell. Intermediate phases have been found in the process of PbTiO3 mechanosynthesis only. The obtained nanopowders were used for preparation of dense ceramics.


2016 ◽  
Vol 69 (1) ◽  
pp. 107 ◽  
Author(s):  
Jingkun Xiao ◽  
Chengwen Song ◽  
Wei Dong ◽  
Yanyan Yin ◽  
Chen Li

Hierarchical flower-shaped Bi2WO6 was obtained by a simple hydrothermal method. Morphology and structure of the Bi2WO6 were characterised by single electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and N2 adsorption techniques. Gas sensing properties of the Bi2WO6 sensor were investigated by a static gas-sensing system. The results show the as-synthesised flower-shaped product is pure orthorhombic Bi2WO6, which is composed of nanosheets with ~10–20 nm in thickness and hundreds of nanometres in planar size. At this optimal operating temperature of 300°C, the Bi2WO6 sensor exhibits ultra-fast response (1-2 s) and fast recovery time (6–12 s) towards ethanol detection, and high selectivity to other gases such as methanol, benzene, dichloromethane, and hexane.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 524
Author(s):  
Hongyou Wan ◽  
Lan Nan ◽  
Huikai Geng ◽  
Wei Zhang ◽  
Huanhuan Shi

The considerable amount of Cr(VI) pollutants in the aqueous environment is a significant environmental concern that cannot be ignored. A series of novel Mxene–CS inorganic–organic composite nanomaterials synthesized by using the solution reaction method was applied to treat the Cr(VI) contaminated water. The Mxene–CS composites were characterized through SEM (scanning electron microscope), XRD (X–ray diffraction), XPS (X–ray photoelectron spectroscopy), and FTIR (Fourier transform infrared). The XRD patterns (observed at 2θ of 18.1°, 35.8°, 41.5°, and 60.1°) and the FT–IR spectra (-NH2 group for 1635 and 1517 cm−1, and -OH group for 3482 cm−1) illustrated that CS was successfully loaded on the Mxene. The effects of solution pH, the dosage of Mxene–CS, and duration time on the adsorption of Cr(VI) by synthesized Mxene–CS were investigated. The removal efficiency of Cr(VI) was increased from 12.9% to 40.5% with Mxene–CS dosage ranging from 0.02 to 0.12 g/L. The adsorption process could be well fitted by the pseudo–second–order kinetics model, indicating chemisorption occurred. The Langmuir isotherm model could be better to describe the process with a maximum adsorption capacity of 43.1 mg/g. The prepared novel Mxene–CS composite was considered as an alternative for adsorption of heavy metals from wastewater.


2009 ◽  
Vol 08 (03) ◽  
pp. 281-283 ◽  
Author(s):  
MASOUD SALAVATI-NIASARI ◽  
FATEMEH DAVAR

Mn3O4 nanocrystals have been prepared using [bis(2-hydroxyacetophenato)manganese(II)] as precursor. Transmission electron microscopy analysis demonstrated nanocrystals Mn3O4 with an average diameter of about 20 nm. The structural study by X-ray diffraction indicates that these nanocrystals have pure tetragonal phase. The phase pure samples were characterized using X-ray Photoelectron Spectroscopy for Mn 2p level. The values of binding energies are consistent with the relative values reported in the literature.


2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 581
Author(s):  
Gajanan S. Ghodake ◽  
Surendra K. Shinde ◽  
Ganesh D. Saratale ◽  
Rijuta G. Saratale ◽  
Min Kim ◽  
...  

The utilization of waste-paper-biomass for extraction of important α-cellulose biopolymer, and modification of extracted α-cellulose for application in enzyme immobilization can be extremely vital for green circular bio-economy. Thus, in this study, α-cellulose fibers were super-magnetized (Fe3O4), grafted with chitosan (CTNs), and thiol (-SH) modified for laccase immobilization. The developed material was characterized by high-resolution transmission electron microscopy (HR-TEM), HR-TEM energy dispersive X-ray spectroscopy (HR-TEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. Laccase immobilized on α-Cellulose-Fe3O4-CTNs (α-Cellulose-Fe3O4-CTNs-Laccase) gave significant activity recovery (99.16%) and laccase loading potential (169.36 mg/g). The α-Cellulose-Fe3O4-CTNs-Laccase displayed excellent stabilities for temperature, pH, and storage time. The α-Cellulose-Fe3O4-CTNs-Laccase applied in repeated cycles shown remarkable consistency of activity retention for 10 cycles. After the 10th cycle, α-Cellulose-Fe3O4-CTNs possessed 80.65% relative activity. Furthermore, α-Cellulose-Fe3O4-CTNs-Laccase shown excellent degradation of pharmaceutical contaminant sulfamethoxazole (SMX). The SMX degradation by α-Cellulose-Fe3O4-CTNs-Laccase was found optimum at incubation time (20 h), pH (3), temperatures (30 °C), and shaking conditions (200 rpm). Finally, α-Cellulose-Fe3O4-CTNs-Laccase gave repeated degradation of SMX. Thus, this study presents a novel, waste-derived, highly capable, and super-magnetic nanocomposite for enzyme immobilization applications.


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